1. Field of the Invention
The invention relates to a contactless monitoring system and, more particularly, to a monitoring system for monitoring an individual seated in a chair.
2. Discussion of the Related Art
As the population ages, an increasing number of people are developing dementia, or disorientation and are in nursing homes or home caregiving situations where falls from a stationary chair, wheelchair, couch, etc. can result in severe injuries. This type of situation is not only dangerous for the demented individual, but can also be very stressful to the caregiver or nursing staff. Since the nursing staff in most facilities or home caregivers cannot continually watch a person who may fall from a chair, they must rely on the assistance of monitors to alert them if a person attempts to leave the chair or has fallen out of it.
Patients in nursing homes and hospitals are often very frail and predisposed to falling. Unfortunately for these patients, the slightest fall may result in a severe, potentially permanent injury that may lead to the deterioration of a person's physical well being and ultimately to his or her death. Many of these falls occur because an individual attempts to stand or walk without assistance. In addition, people may fall asleep in a seated position and gradually slide down, slump or fall forward and then fall out of the seat. This situation is of utmost concern to nursing staffs in hospitals and nursing homes and to home caregivers because it is often difficult to detect the patient's change in condition unless a staff member or caregiver is sitting right next to the individual. Unfortunately, in this time of cost containment and cutbacks of medical personnel, it is often impossible to have a staff member assigned to only one patient. In addition, it is unrealistic to expect a home caregiver to be with a loved one twenty-four hours a day. Accordingly, a simple, inexpensive method of monitoring the movements of a seated patient without requiring a caregiver to constantly observe the patient or loved one is needed.
In addition, the use of the current monitoring systems is often limited to a home or medical facility. Because of the size and complexity of many monitoring systems, they cannot be easily transported or used in a contained area such as a car or other vehicle. Furthermore, the current monitoring systems cannot detect changes in the head and body position such as slumping, slipping or falling backwards, which are indicative of sleepiness and extremely significant for an individual seated in a chair and for the operator of a vehicle.
Numerous methods for preventing falls from chairs or at least for detecting such falls currently exist. For instance, physical restraints are commonly used to prevent the monitored person from exiting a chair, wheelchair or other seating apparatus. Although the use of physical restraints is effective in confining the individual to a specific area, the use of physical restraints results in physical and psychological side effects. These effects include psychological stress resulting from the individual's perceived loss of his or her of freedom and dignity, and physical injury resulting from struggling to be free of the restraints. Physical restraints obviously are of no use in vehicular applications.
Electronic monitoring devices help alleviate many of the physical and psychological side effects resulting from the use of physical restraints and have a wider range of uses. These monitoring systems generally fall into three major categories.
The first category of monitoring system is a weight or pressure detecting system that uses a pressure sensitive pad and controller to detect the weight of a person. To be detected, a person must sit on top of the pad and must be of adequate weight to compress contacts of the pad. Operation of the system depends upon the pad springing back into place when the person leaves the seat. The resulting mechanical action is detected with a mechanical or electronic piezoelectric switch, which sends a signal to a controller that triggers an alarm. There are many drawbacks to this type of system. The alarm is only activated if the monitored individual leaves the chair completely. It also does not provide any mechanism for detecting mere changes in the individual's position indicating an immanent departure. In addition, many of these systems have a time delay before the alarm is sounded to reduce nuisance alarms. Unfortunately, the time delay prevents the alarm from sounding until after the monitored person has already fallen. In addition, the monitoring pads must be replaced frequently because they are easily damaged and rendered inoperable. Pressure activated monitors are often ineffective for small and frail people or children because those people may not be heavy enough to compress the pressure pad sufficiently to activate the alarm.
The second category of monitoring devices or systems utilizes a physical attachment connected between a monitored individual and a controlling device. This system typically requires a clip and string or cord to be attached to the patient's clothes. The other end of the string is connected to a magnet or insert that plugs into the controlling device. When a person attempts to leave the chair, the insert is pulled out of the controlling device to trigger an alarm. There are many disadvantages to this monitoring system. The clip may be removed by the monitored individual, or it can simply fall off the monitored individual. If the clip is removed, the device is rendered ineffective. The string also needs to be of the proper length. If it is too long, it can wrap around the monitored individual and cut off circulation. The attached clip may cause a degree of discomfort that causes the monitored individual to try to remove it. Consequently, nursing staff and caregivers must continually check to make sure the clip is attached to the patient. If the insert is pulled out of the controller, the controller triggers an alarm. Once the alarm is activated, a staff member or caregiver must reset the device and reattach the insert and/or clip even if the monitored individual returns immediately to a seated position.
The third category of monitoring devices or systems use intensity-based measurements of transmitted energy beams to detect if the monitored person is moving into an unsafe area. Under this type of system, a transmitter is positioned in one location near the patient. A receiver is positioned in a second location so that it continually receives the transmitted beam when the patient is in a desired position. If the individual moves outside the desired position, the beam is broken and an alarm is triggered. Although this approach does not require any of the restrictive methods as required in the two previous categories and has a wider range of applications, it only indicates the presence or absence of the monitored individual in the transmitted area. It cannot detect small changes in the patient's position, such as slumping.